Dyeing or coloring of products made with cellulose acetate



one may employ phenols, sulphonic acids, carboxylic acids, phenol sulphonic acids or other derivatives of the benzene, naphthalene or anthracene series containing one or more of any of these groups; or derivatives of other cyclic hydrocarbons, saturated or non-saturated, vcontaining one or more of the above mentioned groups, such for example as the naphthenicacids, naphthene sulphonic acids or other carboxylic or sulphonic acids of the cyclo paraliins; or -one may employ the sodium or other salts of one or more of any of the above mentioned derivatives.

Also it is stated in my said U. S. application S. No. 664,781 that one or more of the solubilizing agents therein referred to may be employed alone or together with one or more of the solubilizing agents referred to' in my first mentioned U. S. application S. No. 664,7 80 for' preparing vthe solubilized modifications of the coloring matters or organic compounds to be applied to the materials or products consisting of or containing cellulose acetate.

It is to be understood thatk other dyes may or may not be employed in combination or association with the coloring matters of the class aforesaid in the same operation or separate operations for the production of compound shades on acetyl cellulose.

' pastes or preparationsrontaining ythickening agents or other appropriate materials.

The practical application Yof the 'present inventionl may be illustrated by' the following example, it being understood that this is given only as an instance and can be varied widely.

EwampZe.-To dye a deep royal blue onA 'Ihe coloring matters of the said class" may likewise be applied for the stencilling lOO kilosLo-acetyl cellulose yarn inhanks.' Add l kilo of caustic soda akes to 1 kilo of dimethyl-para-amido-phenyl-l 4 naphthoquinone monoimide then add 100 litres of waterl at 60 C. Into the mixture sprinkle 2 kilos of sodium hy drosulphite powder and maintain at this v temperature till completely reduced. Filter the solution into a dyebath containing soft water at C., to which have been added 1/2-gram of sodium hydrosulphite per litre'v and 2 cc. of 20% ammonia per litre. Volume of bath about 30:1 calculated on the weight of the goods. Enter the goods and work for 1% hours, maintaining the temperature and addinga little alkali or hydrosulphite from time to time as required lto keep the dyestuli' solution reduced. Then remove the goods and rinse in cold, soft water. Then oxidize in a bath containing 2 grams of sodium perborate per litre, at a temperature of 40 C. for half an hour.

as may be deslred.

Remove the goods, rinse, and finish and dry What I claim and desire to secure by Let- 1. A process for dyeing yarns, threads, fabrics and other products comprising cellulose acetate, said process comprising the ap plication thereto of a coloring vmatter of the y series comprised Within the term indophe- Vnols, in the reduced state.

2. In a process according toclaim l,.the employment of dimethylfrpara-amido phenyl-1:4 naphtho quinone monoimide in the reduced state.

In testimony whereof I have hereunto subscribed my name.

GEORGE HOLLAND 

